The U.S. Patent and Trademark Office in Alexandria Virginia recently hosted a fascinating display of technology. 3D Systems (DDD -1.15%), Stratasys (SSYS -1.11%), and other top companies involved in additive manufacturing, or 3-D printing, displayed their wares in the same room.

Fool analyst Rex Moore was at the conference, and chatted with Stratasys engineer Jim Comb. In this installment of our multi-part series, Jim says that despite being around for many years, this technology is still in its infancy.